PHP日历

通过date函数能够自己写一个日历

<?php
header("Content-type:text/html;charset=utf-8");
echo(date_sunset(time(),SUNFUNCS_RET_STRING,38.4,-9,90,1));
$arr=array('星期一','星期二','星期三','星期四','星期五','星期六','星期日');
$y=$_GET['y']?$_GET['y']:date("Y");
$m=$_GET['m']?$_GET['m']:date("m");
echo "当前是".$y."年".$m."月";
echo "<table border='1' width='60%' align='center'>";
echo "<tr>";
foreach($arr as $val)
{
    echo "<th>".$val."</th>";    
}
echo  "</tr>";
$w=date("N",strtotime($y."-".$m."-01"));
echo "<tr>";
for($i=1;$i<$w;$i++)
{
    echo "<td>&nbsp;</td>";
    
}
$day=date("t");
for($i=1;$i<=$day;$i++)
    {
        $n=date("N",strtotime($y."-".$m."-".$i));
                
         if($n%7==1)
         {
            echo "<tr>" ;    
         }         
         echo "<td>";
         echo $i;
         echo "</td>";
        if($n%7==0) 
        {
            echo "</tr>";
        }
    }
    $n=date("N",strtotime($y."-".$m."-".$day));
    while($n<7)
    {
        echo $n;

        echo "<td>";
        echo "&nbsp";
        echo "</td>";
        $n++;
        
    }
echo "</table>";
$ny=$y+1;
$nm=$m+1;
$by=$y-1;
$bm=$m-1;
?>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<a href=study.php?y=<?php echo $by;?>&m=<?php echo $bm;?>>上一年</a>&nbsp;<a href=study.php?m=<?php echo $bm;?>>上一月</a>&nbsp;<a href=study.php?m=<?php echo $nm;?>>下一月</a>&nbsp;<a href=study.php?y=<?php echo $ny;?>>下一年</a>